Instrument tray for dental operating rooms



y 1962 D. A. HOFFMAN 3,033,628

INSTRUMENT TRAY FOR DENTAL OPERATING ROOMS Filed March 18, 1960 2 Sheets-Sheet 1 QMW ivmf 1.1? min May 8, 1962 D. A. HOFFMAN 3,033,628

INSTRUMENT TRAY FOR DENTAL OPERATING ROOMS Filed March 18, 1960 2 Sheets-Sheet 2 States 3333,62 8 Patented May 8, 1962 3,033,628 INSTRUMENT TRAY FOR DENTAL OPERATDIG ROOMS David A. Hotiman, 2631 N. 95th St., Milwaukee, Wis. Filed Mar. 18, 1960, 591'. No. 16,018 1 Claim. (Ci. 311'-17) This invention relates to dental operating room equipment and refers more particularly to a device for conveniently and readily accessibly supporting dental instruments at any desired location and position in the neighborhood of a dentists operating chair.

Heretofore the standard equipment in a dentists operating room has included a fountain pedestal secured to the floor adjacent to the operating chair and which supported several pieces of apparatus including a tray for holding instruments that the dentist intended to put to immediate use in work being performed. The instrument tray was swingable edgewise through a restricted are which carried it approximately over the patients thighs, and the dentist, when working from in front of the patient, was required to turn through an angle of about 45 in order to reach an instrument on the tray. From a position behind the patient it was necessary for the dentist to take two or three steps in order to reach the instrument tray.

The change in position and posture and the loss of time involved in picking up and laying down instruments on such a tray consumed both nervous and physical energy, but this was not the only disadvantage of the prior arrang ment. Ordinarily the area around the patients head is very brightly lighted, to provide suflicient illumination for the close and minute work involved in dental practice, while the area around the pedestal mounted instrument tray was lighted with substantially less intensity. As a result of this difference in illumination levels, the dentists eyes changed their light adaptation adjustment as he looked away from the patients head to the instrument tray, and again when he looked back at the patient. The necessity for constant readaptation to different lighting intensities during the course of work on a patient was a source of fatigue and annoyance, and one that was particularly insidious because no conscious effort is involved in changing the iris diameter to accommodate the eye to ditierent light levels, but a noticeable time interval is required for each such readaptation to take place.

With the foregoing in mind it is a general object of I this invention to provide a supporting device by which a group of dental instruments may be readily moved to and held at locations where they will at all times be convenient to a dentist while he is working on a patient, including locations directly alongside the patients head;

Another object of the present invention is to provide a device for supporting a number of dental instruments or the like, which device is adjustable to enable the instruments to be very readily moved, as a group, from one location to another around a dentists operating chair, and particularly to positions closely adjacent to the patients head, so that all of the instruments required for a particular operation may be directly at hand and within the field of illumination that is lighting the area of the work being done, where instruments can be readily picked up and laid down as the progress of the work requires withv out any need for substantial change in the dentists position or posture and without requiring him to refocus his eyes on zones of substantially different light intensities.

Another important object of this invention resides in the provision of a supporting device for dentists instruments and the like which occupies no floor space and which can be readily moved from place to place in the neighborhood of the operating chair at any time that the dentist finds it desirable to change his position, without any interference from or with the chair or a patient seated therein, so that instruments carried on the device will always be within easy reach of the dentist.

It is also an object of this invention to provide supporting means for holding a tray at any of a wide range of locations, heights, and positions, which supporting means occupies no floor space and therefore does not interfere with use of the floor area beneath the tray, and leaves the entire upper surface of the tray completely open and unobstructed.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination andarrangement of parts substantially as hereinafter described and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claim. 7

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIGURE 1 is a perspective view of the device of this invention installed in a dentists ollice and shown in relation to the operating chair; and

FEGURE 2 is a view of the device, partly in side elevation and partly in longitudinal section.

Referring now particularly to the accompanying drawings, the numeral 5 designates generally the dental instrument holder of this invention, which comprises, in general, a mounting head 6 adapted to be fastened tothe ceiling 7 of a dental operating room, over the operating chair 8, a telescopingly extensible and retractable leg 9, the up per end of which is connected with the mounting head by a ball and socket joint 10 and a tray 11 connected to the lower end of theleg by another ball and socket joint 12.

It will at once be apparent that the ball and socket connection lit between the leg 9 and the mounting head 6 provides for universal swinging adjustment of the leg to permit the tray to be moved laterally to practically any desired location in the neighborhood of the operating chair, while the telescoping of the leg provides for adjustment of the height above the floor at which the tray is situated, and the lower ball and socket connection 12 provides for adjustment of the attitude of the tray.

The mounting head 6 is substantially T-shaped. Its cross bar portion 14 has holes 15 to receive screws 16 by which the mounting head may be secured to the ceiling 7 of a room, or, if preferred, to a mounting plate which can in turn be fixed to the ceiling. The downwardly projecting stem portion of the T-shaped mounting head provides a boss 18 over which is telescoped a closely fitting collar 1% that supports the socket member 26 of the upper ball and socket joint it). Screws 21, or the like, extending radially inwardly through the wall of the collar and threaded into the boss .18, secure the collar to the mounting head.

The socket member 20 is rotatably supported in the collar 19 by means of cooperating oppositely facing circumferential shoulders provided by a radially outwardly projecting circumferential flange 22 on the top of the socket member and a radially inwardly projecting circumferential flange 23 on the bottom of the collar. The outside diameter of the flange 22 on the socket member is substantially equal to the diameter of the bore in the collar, and the outside diameter of the main portion of the socket member is substantially equal to the inside diameter of the flange 23 on the collar, so that the socket member can rotate smoothly in the collar with no tendency to tilt.

The ball member 24 ofthe upper ball and socket connection comprises a substantially spherical head 25, which is seated in the socket member 2d for universal swiveling motion, and an integral stem portion 27 which projects downwardly out of the socket member to connect the ball member with the leg 9. The socket member has a coaxial bore 28 therethrough of substantially the same diameter as the head 25 of the ball member, but at its bottom the socket member has a radially inwardly projecting circumferential fiange 2 defining an annular upwardly facing shoulder upon which the head 25 seats. The upper surface of this flange is beveled'to mate with the spherical surface of the head 25, thus enabling the ball member to have smooth universal swiveling motion in the socket member.

The socket member has a lengthwise extending slot 30 in its wall, at one side thereof, opening to its lower end, which is wide enough to receive the stem of the ball member to permit the latter to be swung to an angle at which the leg 3 is disposed nearly horizontally. Because of the rotatability of the socket member 20 in the collar, the leg thus has a wide range of universal swinging motion.

The stem portion 27 of the ball member 24 of course has a smaller diameter than that of its spherical head portion 25, so that the ball member can be inserted into the socket member 20 from the top of the latter. The socket member is likewise axially inserted into the collar 19 from the top of the latter.

To insure that the leg 3 will tend to remain in any position of swinging adjustment to which it may be moved, -a plunger-like friction shoe 32 is at all times urged against the head of the ball member by means of a very stilt coiled compression spring 31 that reacts against the mounting head 6. The friction shoe has a cylindrical head 34 of a diameter to be loosely slidable axially in the bore 28 of the socket member, and which is concave at its underside so as to make good frictional engagement with the spherical head 25 of the ball member in all positions of the latter. Projecting upwardly from the head portion 34 of the friction shoe is a concentrc smaller diameter stem portion 33 which is embraced by the lower portion of the spring 31. The upper end portion of said spring is received in and steadied by a shallow, concentric downwardly opening well 35 in the boss 18 on the mounting head, while its lower end bears downwardly upon the head of the friction shoe.

The leg 9 consists of a plurality of telescoping tubular members and means for readily releasably locking said members in any of a wide range of positions of telescop- 1 ing extension and retraction. Preferably the leg comprises a sleeve 36, an upper extension member 37 telescoped into the upper portion of the sleeve, a first lower extension member 38 telescoped into the lower portion of the sleeve, and a second lower extension member 39 telescoped into the first lower extension member 38. The upper extension member 37 and the first lower extension member 33 have outside diameters slightly smaller than the inside diameter of the sleeve 36, so as to be smoothly telescopingly slidable therein, and the sleeve has inwardly rolled circumferential ridges 40 near each of its ends, adapted to be engaged by outwardly flared shoulders (not shown) on the inner ends of the extension members 37 and 38 to prevent said extension members from being withdrawn completely out of the sleeve. Similarly, the second lower extension member 39 has an outside diameter slightly smaller than the inside diameter of the first lower extension member 38 so as to be smoothly telescopingly slidable in the latter, and has an inwardly rolled circumferential ridge 42 near its outer end adapted to be engaged by an outwardly flared shoulder (not shown) on the second lower extension member 39.

The ball member 24 of the upper ball and socket joint has a cylindrical lower end portion 48 which is telescoped into the upper end portion of the upper extension member 37, and screws 49, or the like, extending radially inward- 1y through the wall of the tubular member 37 and threaded into the ball member, fasten the leg to the upper ball and socket joint.

Threaded onto both ends of the sleeve 36 and onto the outer end of the first lower extension member are locking nuts 44 by which each element of the leg may be readily releasably locked in any desired position of tele' scoping adjustment. Each of the locking nuts is adapted to project axially beyond the end of the member onto which it is threaded, and the projecting portion of the locking nut has a radially inwardly projecting circum ferential flange 45. The member on which each nut is threaded has a beveled inner surface 46 at its end adjacent to the nut, and confined betweenthe nut and the extension member with which it lockingly cooperates is a split ring 47 of fibre or the like. As each nut 44 is drawn up onto its thread, the flange 45 on the nut forces the split ring 47 into engagement with the beveled surface 46, thus imposing a'wedging force upon the split ring which clamps the latter into secure frictional engagement with the extension member that it embraces, locking the extension member against axial movement relative to the tubular member on which the nut is threaded. The outer surfaces of the nuts are preferably knurled so as to permit them to be readily turned, and it will be recognized that each nut need be rotated through only a fraction of a turn to either lock or release its cooperating extension member.

The locking nut 44 which provides for adjustment of the upper extension member 37 will normally be situated at a height where it will not be readily accessible, but this is not an actual disadvantage because the upper extension member is mainly provided to accommodate the device to installation in operating rooms having various ceiling heights. Once the installation is made there will be little or no occasion to make further adjustments to the upper extension member, since the two lower extension members 38 and 39, which are always readily accessible, provide for a sufficient range of adjustments of the length of the leg 9 to meet all ordinary requirements.

The lower ball and socket joint 12 provides for adjustment of the tray ll to any desired attitude, so that the tray may be maintained substantially horizontal and upright in any position to which the leg 9 may be swung or swiveled.

The connection between the ball and socket joint 12 and the second lower extension member 39 is provided by a substantially T-shaped connector 49, the stem portion 50 of which is telescoped into the lower end portion of the second lower extension member 39 and secured thereto by screws 51 or the like extending radially inwardly through the extension member and threaded into the connector. The cross member 52 of the connector provides a collar in which the socket element 53 of the lower ball and socket joint is rotatably carried.

As in the case of the upper ball and socket joint, the collar 52 has a radially inwardly projecting circumferential flange 54 at one axial end thereof which cooperates with a radially outwardly projecting circumferential flange 55 on the axially inner end of the socket element 53 to constrain the latter to rotation in the collar, and the socket element has a bore 56 therethrongh which is of substantially the same diameter as the spherical head 57 of the ball element 58. A small radially inwardly projecting circumferential flange 59 at the axially outer end of the socket element provides a beveled inwardly facing surface upon which the head 57 of the ball element is seated for universal swiveling motion. The ball element 58 also includes a stem portion 60 which provides a connection between the tray 11 and the lower ball and socket joint. An axially extending slot 61 in the wall of the socket element, opening to its axially outer end, can receive the stem portion 60 of the ball element to provide a substantially wide range of angles through which the ball element may be adjusted.

To enable the lower ball and socket joint 12 to be releasably locked in any position of swiveling and swinging motion to which it may be adjusted, manually adjustable means .are provided for applying friction to the spherical head 57 .of the ball element. Preferably this comprises a plunger-like friction shoe 64 and a locking screw 62 by which the shoe may be forced into engagement with the head of the ball element. The locking screw 62 is coaxially threaded through a bushing 63 secured to that axial end of the collar which is remote from the socket element 53, and is provided at its outer end with a large hand wheel 68 or the like to facilitate its manual rotation.

The friction shoe 64, which is cylindrical, fits loosely in the inner end portion of the bore 56 in the socket element 53, and it has a concave end surface 65 that engages the head of the ball element with good frictional contact. A disc 66, fitting loosely in the bore in the collar portion of the connector, transmits tightening force of the locking screw 62 to the friction shoe. It will be observed that the friction shoe has sufficient length to project inwardly a short distance beyond the axially inner end of the socket element, to insure that the disc 66 will not bottom on the socket element.

The socket element 53, ball element 58, friction shoe 64 and disc 66 are held properly assembled with one another and in the collar portion 52 of the connector by means of a bowed leaf spring 67 which lies inwardly adjacent to the disc 66 and has its ends engaged with the wall of the bore in the collar portion 52. Specifically, the leaf spring 67 has a generally rectangular shape, but its end portions are rounded on radii substantially conforming to the radius of the bore in the socket portion 52. Because the length of the leaf spring is slightly greater than the diameter of the bore in the collar 52, the ends of the leaf spring bite into the wall of the collar and bow its medial portion slightly toward the disc 66, thereby holding the spring, and the disc therebeneath, against inward displacement when the locking screw 62 is loosened by turning it outwardly away from the disc. Obviously, however, when the locking screw is tightened against the medial portion of the leaf spring 67, the latter bowingly flexes toward the disc, transmitting the inward force exerted by the locking screw to the disc and thus to the friction shoe to urge the same into engagement with the spherical head of the ball element 58.

The tray 11 may be of any desired shape, but is preferably rectangular, with a shallow rim 70 around it and a laterally outwardly projecting lip 71 extending around the rim. Desirably the tray is made of stainless steel or similar hard, smooth material.

The tray is secured to the outer end of the stem portion 60 of the ball element by means of an L-shaped bracket 72 secured to the underside of the tray near one end thereof. One leg 73 of the bracket flatwise underlies the bottom of the tray and is secured thereto as by spot welding, while the other leg 74 projects upwardly to the lip 71 and has a threaded hole therein, on the longitudinal centerline of the tray, in which is engaged the threaded outer end portion 72 of the ball element. It will be seen that the connection provided by the bracket 72 in effect cantilevers the tray from the leg 9, leaving the entire upper surface of the tray clear and unobstructed.

Obviously, adjustment of the tray to change its position merely involves manually swinging the leg 9 about the upper ball and socket joint, loosening the locking screw 62 with one hand while holding the tray with the other, and retightening the locking screw when the tray is in the desired attitude. Adjustment of the attitude of the p and telescopingly extending or retracting the leg to position the tray where it is Wanted. It will be observed that such lengthening or shortening of the leg resultsin purely translatory motion of the tray, so that the device can be adjusted as to tray height without danger that the tray will tilt and drop any instruments it may be carrying.

From the foregoing description taken together with the accompanying drawings, it will be apparent that this invention provides a simple, rugged and easily adjusted device for supporting dental instruments or the like at any desired position and location in the vicinity of a dentists operating chair, without interference from or with a chair or a patient seated in the chair, so that instruments needed by a dentist can at all times be conveniently located very close to the site of the work being performed, and within the field of light illuminating the work, to thus minimize changes of position and posture of the dentist and readjustment of his eyes to lighting of substantially different intensities. It will also be apparent that the device of this invention supports a tray for dental instruments in such a manner as not to interfere with other use of floor space beneath the tray and leaves the upper surface of the tray completely clear and accessible.

What is claimed as my invention is:

Means for readily accessibly supporting dentists instruments or the like at any of a number of positions in a room without occupying floor space, said means comprising: a mounting head having means thereon for attaching the same to a ceiling; an adjustably extensible and retractable leg comprising at least three leg elements coaxially telescoped into one another, each of said leg elements that has another telescopable into it being threaded at its end from which said other leg element projects; a locking nut threaded onto said end portion of each of the threaded leg elements and having a portion which projects axially beyond the threaded leg element, which portion of the locking nut has a convergingly tapered inner surface; radially compressible means confined between said axially projecting portion of each locking nut and said other leg element for bringing pressure substantially uniformly upon the circumference of said other leg element upon tightening of the locking nut, to thus releasably lock said other leg element against endwise extension and retraction relative to that upon which the locking nut is threaded; cooperating means on the mounting head and on one end of said leg providing a ball and socket connection universally swingably and pendantly supporting the leg from the mounting head; friction means on said ball and socket connection for yieldingly inhibiting swinging motion of the leg relative to the mounting head so that the leg tends to resist displacement out of any position of adjustment to which it may be swung; an elongated tray; a connector having a portion which is substantially coaxially secured to the leg at the other end thereof and having another portion which'projects laterally in one direction with respect to the leg; cooperating means on one marginal end portion of the tray and on said other portion of the connector providing a second ball and socket connection, between the tray and said other end of the leg, by which the tray is supported by the leg for universal swiveling and swinging motion about a center spaced to one side of the leg axis; and frictional locking means on the connector, cooperable with the last named ball and socket connection means for releasably holding the tray in any desired position of swinging and swiveling adjustment relative to the leg, thus enabling the tray to be disposed in a substantially horizontal position regardless of the angle at which the leg is inclined, said frictional locking means including a screw which projects from the connector in another direction lateral to the leg and which has an actuator on its projecting end portion by which it can be manually tightened and loosened.

References Cited in the file of this patent UNITED STATES PATENTS Hoople June 6, 1933 Tramrnell June 6, 1950 Vroom Jan. 1, 1952 French et al. Mar. 20, 1956 Galloway Mar. 18, 1958 French June 28, 1960 

